The invention relates to wheel hub assemblies in general and to a wheel hub assembly having a bearing retainer ring in particular.
Wheel hub assemblies found on the non-driven axles of motor vehicles generally include the wheel hub itself and a bearing. A press-fit mounting is typically used to position the bearing within an inner bore that extends through the hub body. The bearing inner race is fixed to the axle whereas the outer race rotates with the vehicle wheel. Because of the vibration and suspension loads that are imparted through the wheel hub assembly during operation, it is necessary to further secure the bearing in the hub, usually through the use of an element producing positive mechanical retentions. Known positive retention elements typically provides a pre-load, axial retention force onto the bearing.
One popular method of retaining the wheel bearing is to use a snap ring or C-clip. The snap ring is installed into an undercut groove which has been machined into the inner bore of the hub. However, the undercut groove is a difficult and costly feature to machine into the hub. Additionally, material chips from the machining process can become entrapped within the undercut groove and impede assembly of the bearing and snap ring.
Another mechanism for retaining and providing a pre-load retention force on the bearing utilizes a bearing retainer ring or bracket. Dedicated fasteners secure the bracket to the wheel mounting flange of the hub. A spacer or intermediate member is positioned between the bearing and bracket and transmits axial retention loads from the bracket to the bearing.
One limitation of the above prior retaining designs is that use of the dedicated fasteners and intermediate members increase the overall weight of the wheel hub assembly. Another limitation is that the dedicated fasteners and intermediate members increase the bulk of the wheel hub assembly. Furthermore, the use of dedicated fasteners requires additional machining of the wheel mounting flange which results in increased production costs. Typically, this machining produces additional bores drilled or otherwise formed in the wheel mounting flange. The present invention is a direct improvement over these bearing retainer rings.
It is a principal object of this invention to provide for a wheel hub assembly in which axial retention loads are maintained on the bearing. As such, the present invention overcomes the limitations of the prior bearing retainer methods.
It is also an object of this invention to provide a wheel hub assembly which is cost efficient to produce. In reducing costs, the present invention simplifies the production and assembly processes by reducing the number of production steps and the number of individual parts used in wheel hub assembly. A related object is to reduce the overall weight and bulk of the wheel hub assembly.
In achieving the above and other objects, the present invention provides a wheel hub assembly for a non-driven axle. Generally, the assembly includes a hub, a bearing and a retaining ring.
The hub includes a cylindrical main body having a central bore extending axially therethrough. A portion of the central bore defines a bearing seat which receives the pre-set and prelubricated bearing. A wheel mounting flange, including wheel mounting bores spaced around the flange, extends radially outward from the main body of the hub. The bearing retainer ring is secured to the hub by the engagement of the wheel mounting studs in the wheel mounting bores. A loading portion of the retainer ring directly contacts and provides a positive axial retention load on the bearing.
The present invention eliminates the dedicated fasteners and spacers associated with the prior designs and results in a structure that provides for a compact and light weight wheel hub assembly which is simplified in construction and cost effective to produce.
Additional benefits and advantages of the present invention will become apparent to those skilled in the art to which this invention relates from the subsequent description of the preferred embodiments and the appended claims taken in conjunction with the accompanying drawing.